using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yukicoderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            int num = 0;
            for(int i=0;i<input.Length;i++)
            {
                string temp = input.Substring(i, 1);
                if(temp=="0")
                {
                    num = num + 10;
                }
                else
                {
                    num = num + int.Parse(temp);
                }
            }
            Console.WriteLine(num);

        }
    }
}